Abstract
The usual goniometer head is often not suitable for use on a four-circle diffractometer because it obstructs the incident of reflected X-ray beams. A range of settings of the circles may be made impossible because of collisions between the goniometer head and the collimator. To overcome this difficulty the crystal is first orientated on the usual goniometer head, using photographic or diffractometric equipment, and then transferred to a support consisting of a single thin cylindrical rod.
The apparatus for this purpose consists of two collinear axles provided with standard goniometer head bases. The crystal is mounted on a glass fibre and a method is described by which the fibre and crystal may be transferred from one head to the other without change of orientation relative to the common axis of the axles.